Question about veins, my veins are really showing tonight and one spot of my leg hurts and. What could this be?

DVT, varicose, etc. Painful veins could be many things including: varicose veins, blood clot (superficial or deep -- dvt), thrombophlebitis (inflammation/infection of the veins), an underlying muscle injury, underlying cyst, etc. See you md to evaluate.
Blood clot. This could also be something call superficial venous thrombosis (svt) or phlebitis. I would recommend that you are evaluated by your physician to differentiate from other possiblities such as DVT which was mentioned by dr. Thompson.
Varicose veins. Pain that came on quickly may be due a blood clot of the varicose vein or of a deep vein. Other causes of leg pain include musculoskeletal problems. You should be evaluated by a physician, to include a duplex ultrasound. If the pain has been longstanding, it may be due to the varicose vein itself. There are excellent minimally-invasive treatments for varicose veins. See a phlebologist/vein dr.